Apparatus and method for moving or positioning wider or narrower of objects

ABSTRACT

An apparatus is for displacing objects which can be picked up. The apparatus includes a fork-like member provided with teeth for picking up the objects, a transporting device connected to this member, a device for moving the fork-like member vertically, and a control device for controlling the transporting and moving devices. The apparatus includes at least one pair of mutually adjacent teeth of the fork-like member which is equipped with one flexible carrier arranged on each tooth and drivable in longitudinal direction of the tooth. When the objects are set down, this carrier can impart a determined speed to the objects such that the distance between two rows of set-down objects standing perpendicularly of the direction of the teeth can be regulated in a flexible manner by way of adjusting the speed of the carrier.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/NL02/00818 which has an Internationalfiling date of Dec. 11, 2002, which designated the United States ofAmerica and which claims priority on Dutch Patent Application number1019537 filed Dec. 11, 2001, the entire contents of which is herebyincorporated herein by reference.

FIELD OF THE INVENTION

The invention generally relates to an apparatus for displacing objectswhich can be picked up. This may include an apparatus, comprising:

-   -   a fork-like member provided with teeth for picking up the        objects,    -   transporting device connected to this member,    -   device for moving the fork-like member vertically,    -   control device for the transporting and moving devices.

BACKGROUND OF THE INVENTION

Apparatuses are generally known in the form of a fork-lift truckequipped with a fork, and are traditionally used in the displacement ofobjects such as flower pots. These objects must be provided with an edgeor protruding portion allowing it to be picked up between the teeth ofthe fork. The standard flower pot for instance comes to mind here whichis embodied as a pot with a protruding portion.

In the displacement of objects it may be advantageous to change thearrangement of the objects, and it may sometimes be wished to place theobjects further apart or closer together. When the above describedapparatus is used in a plant nursery, it will be desired for instance tobe able to place the plant pots wider apart so that the growth of theplants is enhanced.

Such an apparatus can be embodied for this purpose with flaps arrangedon the teeth, as known from the document 890 237 7. These flaps can bedriven such that not all objects are set down simultaneously, but forinstance one of two rows of objects are placed and the objects held onthe fork by the flaps can be placed elsewhere. Objects can hereby be soplaced wider apart, but the distance between the placed objects cannothere be adjusted as a variable.

SUMMARY OF THE INVENTION

The apparatus according to an embodiment of the invention, has devised amore convenient solution herefor, and proposes a new system which hasthe feature that at least one pair of mutually adjacent teeth of thefork-like member is equipped with one flexible carrier arranged on eachtooth and drivable in longitudinal direction of the tooth. When the potsare set down this carrier can impart a determined speed to the pots suchthat the distance between two rows of set-down pots standingperpendicularly of the direction of the teeth can be regulated in aflexible manner by way of adjusting the speed of the carrier.

The carrier can for instance be embodied, according to an embodiment ofthe invention, as a toothed belt or chain.

When such a carrier is loaded with the weight of the pots, it may happenthat forces are exerted in the transverse direction of the carrier. Inorder to prevent the carrier shifting here, it is preferably equippedwith a device for holding the flexible carrier in its place relative tothe teeth in the case of transverse load.

In the case of for instance a chain, this can be provided with fingersfor holding the chain in its place relative to the teeth in the case oftransverse load.

In one embodiment of the invention, one flexible carrier is arranged onall teeth of the fork-like member, wherein these carriers are preferablydriven by one common drive shaft. In this way the cost of the apparatusis limited to a minimum.

It will be the wish to be able to adjust precisely the mutual distancebetween the successive rows of objects for placing. In order to regulatethis distance, the apparatus according to an embodiment of the inventionis provided with a controller which can adjust the speed of the flexiblecarriers.

It is particularly advantageous if this controller can regulate thespeed of the flexible carriers as a function of the speed of thetransporting device. It is thus possible for instance to constantlyregulate the net speed of the objects relative to the position where theobjects come to stand, and the mutual distance between the set-down rowsis determined by this constant speed and the original mutual distance.

An embodiment of the invention may further relate to a method fordisplacing objects which can be picked up, wherein a fork-like memberprovided with teeth picks up and subsequently sets down objects atanother location.

As already stated above, it can be advantageous here to place theobjects further apart or closer together. For this purpose the methodaccording to an embodiment of the invention is distinguished byregulating the speed of the objects relative to the teeth, duringpicking up or setting down of the objects which can be picked up, by wayof flexible carriers movable in longitudinal direction on the teeth,wherein each tooth has a maximum of one carrier. The regulating of thisspeed thus adjusts the mutual distance between the rows of objects setdown perpendicularly of the tooth direction.

In the method according to an embodiment of the invention, it is usualfor all the objects to be picked up at the same time by the fork and tobe transported to the destination. The speed of the picked-up objectsrelative to the teeth is then regulated so as to be lower than thetransporting speed of the teeth such that the set-down objects are setdown in rows where the mutual distance between the rows is greater thantheir mutual distance when the objects are picked up.

In the preferred method the objects for picking up are disposed in acheckerboard pattern. This is a much used arrangement in plantnurseries, since a determined space is thus provided between the potswhereby the plants can grow unimpeded. After a time however the plantswill increase in size and it will be desired to place them even furtherapart.

To this end, according to a method of an embodiment of the invention,the plants can all be picked up simultaneously and then be set downelsewhere, wherein the speed of the flexible carrier relative to theteeth is regulated during setting down such that the set-down objectsfrom two adjacent rows have a mutual distance which is greater thantheir mutual distance in the original checkerboard pattern.

It will sometimes also be desired to place objects closer together. Inthe case of plant pots this could be the case when it is wished totransport the plants to a shop or market, and as many pots as possibleare preferably transported simultaneously in a truck.

For placing together of objects, an embodiment of the invention providesa method wherein the speed of the flexible carrier relative to the teethduring setting down is regulated by means of the controller so as to behigher than the transporting speed of the teeth such that the set-downobjects have a mutual distance which is smaller than their mutualdistance when the objects are picked up.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention will becomeevident from the description of illustrated embodiments givenhereinbelow and the accompanying drawings, which are given by way ofillustration only and thus are not limitative of the present invention,wherein:

FIG. 1 is a perspective view of an apparatus according to an embodimentof the invention;

FIG. 2 shows a cross-section of three teeth of an apparatus according toan embodiment of the invention which are picking up pots;

FIG. 3 shows a section in longitudinal direction of a tooth of anapparatus according to an embodiment of the invention;

FIG. 4 shows a section in transverse direction of a tooth of anapparatus according to an embodiment of the invention;

FIG. 5 shows a series of pots disposed in a checkerboard pattern, andthe resulting pattern after picking up and subsequently setting-down thepots according to a method of an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a fork-lift truck 1 provided with a fork 2 with teeth 3.Each tooth 3 is equipped with a flexible carrier 4 which is coupled by adrive wheel to a common drive shaft 6, whereby carriers 4 are movable inlongitudinal direction relative to teeth 3.

This flexible carrier can be formed by a chain or a belt, wherein thechoice depends among other things on the nature of the objects it iswished to transport, and of course also on the cost-price of the twotypes of carrier.

Carrier 4 can for instance be arranged on tooth 3 by way of drive wheel5 and three guide wheels 7, 8, 9 as shown in FIG. 3.

FIG. 4 shows in cross-section a carrier 12 embodied as a chain, whereinsome of the links of the chain are provided with fingers 13 so that thechain does not come off under transverse load. The tooth is provided onthe sides with rods 14 for the bearings of guide wheel 7.

The objects for moving are for instance flower pots 10 with an edge 11which can be picked up between teeth 3, wherein the edges 11 support oncarriers 4 as shown in FIG. 2.

Machines are generally available in plant nurseries which set down theplant pots in a checkerboard pattern, since it has been found that thispattern is very suitable for a uniform, unobstructed growth of theplants. After a time however, the plants will have increased in size andit will be desired to place them even further apart.

FIG. 5 illustrates a preferred method of an embodiment of the invention,wherein the pots 10 in a checkerboard pattern are all picked upsimultaneously by fork 2 (FIG. 5A). This takes place by carrying thefork downward to a height where the teeth lie lower than the edge of thepots. The driver then moves in the direction of the rows of pots suchthat the teeth lie along the edges of all pots for transporting. Thefork is then moved upward, and the pots can be transported by fork-lifttruck 1 to the desired destination. Upon arrival at the desireddestination the fork is moved downward such that the pots almost touchthe ground. The fork-lift truck then reverses and the carrier is drivenat a speed which is lower than the speed at which the truck isreversing.

In this manner the pots are pushed row by row from the carriers and theset-down objects from two mutually adjacent rows have a mutual distancewhich is greater than their mutual distance in the original checkerboardpattern, as shown in FIG. 5B.

The speed of the carriers during setting down of the pots can either beregulated constantly or regulated as a function of the travel speed ofthe fork-lift truck. This latter method is particularly useful becausethe driver does not then have to reverse at a constant speed duringsetting down, and the pots can still be placed wider apart at a constantdistance between the rows.

The lower the carrier speed is regulated as a function of the reversingspeed, the further apart the rows will come to stand, wherein the mutualdistance between two rows can thus be precisely adjusted, and is givenby the product of the original mutual distance and the quotient of thefork-lift truck speed and the carrier speed. This quotient thusdetermines the difference in mutual distance between two rows before andafter the pots are set down, and this quotient must therefore beregulated constantly if it is wished that this difference be constant.

This method can of course be repeated many times in order to place thepots further and further apart as the size of the plants increases. Theplants can also be placed closer together again when it is wished forinstance to transport them to a market or a shop. The method is hereinidentical to that described above, with the difference that the carrierspeed must be regulated so as to be faster than the reversing speed ofthe fork-lift truck during the setting-down.

The invention is of course not limited to the above describedembodiments, and can for instance be modified for the purpose of pickingup other objects, or can be embodied with different drive shafts,whereby the carriers can be driven at a different speed. Many othervariants can thus be envisaged which all fall within the domain of theinvention.

Exemplary embodiments being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

1. Apparatus for displacing objects which can be picked up, comprising:a fork-like member provided with teeth for picking up the objects,transporting device connected to this member, device for moving thefork-like member vertically, control device for the transporting andmoving devices, wherein at least one pair of mutually adjacent teeth ofthe fork-like member is equipped with one flexible carrier arranged oneach tooth and drivable in longitudinal direction of the tooth. 2.Apparatus as claimed in claim 1, wherein the flexible carrier isprovided with means for holding the flexible carrier in its placerelative to the teeth in the case of transverse load.
 3. Apparatus asclaimed in claim 1, wherein the flexible carrier is a toothed belt. 4.Apparatus as claimed in claim 1, wherein the flexible carrier is achain.
 5. Apparatus as claimed in claim 4, wherein the chain is providedwith fingers for holding the chain in its place relative to the teeth inthe case of transverse load.
 7. Apparatus as claimed in claim 1, whereinthe transporting and moving devices are a fork-lift truck.
 8. Apparatusas claimed in claim 1, wherein one flexible carrier is arranged on allteeth of the fork-like member.
 9. Apparatus as claimed in claim 8,wherein all flexible carriers are driven by of a common drive shaft. 10.Apparatus as claimed in claim 1, wherein the speed of the flexiblecarriers is adjusted via a controller.
 11. Apparatus as claimed in claim10, wherein the speed of the flexible carriers can be regulated as afunction of the speed of the transporting device using the controller.12. Method for displacing objects which can be picked up, wherein afork-like member provided with teeth picks up and subsequently sets downobjects at another location at a determined transporting speed,comprising: regulating, during at least one of picking up and settingdown of the objects, the speed of the objects relative to the teethusing flexible carriers movable in longitudinal direction on the teeth,wherein each tooth has a maximum of one carrier.
 13. Method as claimedin claim 12, wherein the objects are all picked up at the same time, andwherein, when the objects are set down, the speed of the picked-upobjects relative to the teeth is regulated so as to be lower than thetransporting speed of the teeth.
 14. Method as claimed in claim 13,wherein the objects for picking up are disposed in accordance with acheckerboard pattern consisting of rows placed perpendicularly of theforks, and wherein the speed of the flexible carrier relative to theteeth is regulated during setting down such that the distance betweentwo set-down rows is greater than their mutual distance in the originalcheckerboard pattern.
 15. Method as claimed in claim 12, wherein theobjects are all picked up at the same time, and wherein the speed of theflexible carrier relative to the teeth during setting down is regulatedso as to be higher than the transporting speed of the teeth. 16.Apparatus as claimed in claim 2, wherein the flexible carrier is atoothed belt.
 17. Apparatus as claimed in claim 2, wherein the flexiblecarrier is a chain.
 18. Apparatus for displacing objects, comprising:first means, provided with teeth, for picking up the objects; and meansfor moving the first means vertically, wherein at least one pair ofmutually adjacent teeth of the first means is equipped with one flexiblecarrier arranged on each tooth and drivable in longitudinal direction ofthe tooth.
 19. Apparatus as claimed in claim 18, further comprising:means for transporting the first means; and control means forcontrolling the means for transporting and the means for moving. 20.Apparatus as claimed in claim 18, wherein the flexible carrier isprovided with means for holding the flexible carrier in its placerelative to the teeth in the case of transverse load.